This is perhaps THE very most simple and very most helpful design rule of all:

Do use 100nF decoupling capacitor for each digital or analog chip!

And I cannot understand, that this could be the subject of any discussion!
Of course, there are some situations where some of these capacitors MAY be neglected. But why wasting time to think about the possibility of being able to neglect a decoupling capacitor here and there? This makes absolutely no sense!!!
Adequate decoupling is sooooooooooooooooooo helpful, that even the wish to avoid some of these decoupling capacitors is absolutely stupid!!
Don't you have enough area on your PCB? NO! Or would the extra costs of some cents ruin your company? NO! So, why discussing this subject????

There are thousands over thousands of publishings focusing the benefit of adequate power supply decoupling. There's a whole industry doing nothing else than to optimize decoupling and filtering techniques. Seminars over seminars are given about this subject. etc. etc. etc.
Behind this background your question sounds bloody, bloody amateurish!!

-100 points!

Kai